Progressive cavity pump style motors exist and have been employed in conjunction with power sections of drilling tools. These motors employ stators having one more lobe than associated rotors. There exists a trend to increase the number of lobes in the rotors and stators. However, increasing the number of lobes leads to complicated geometries and generally increases the costs of manufacturing such motors. Additionally, employing motors having an increasing numbers of lobes leads to low speed, high torque power generation modules.
Directional drilling tool drive trains utilize a single drilling fluid motor power section or multiple power sections arranged in series driving around a bend through a constant velocity shaft or solid torsion shaft.